Satellite Health
8
H|0|perform|mission operators|398|414|
H|0|battery|battery|671|677|
G|0|tlc|TLC|919|921|
H|0|hga|high-gain antenna|1096|1112|
H|0|record|tape recorders|1127|1140|
H|0|esam|ESA|1151|1153|
H|0|solar|solar panels|1396|1407|
G|0|gimbal|gimbals|1114|1120|
    Component degradation and failure are a natural part of life for every space mission. Violent launches, solar and cosmic radiation, temperature extremes, and mechanical wear all take their toll on satellite hardware. Spacecraft designers combat these problems by building redundancy into their systems, but degradation and failure are impossible to avoid completely. Therefore, TOPEX/Poseidon mission operators carefully monitor component performance in order to spot trends in degradation and develop special management techniques and work-arounds to prolong satellite health. 
    One of these special techniques was implemented due to the abnormal degradation of battery cells in other spacecraft that are using batteries similar to TOPEX/Poseidon's. To insure against this problem occurring on TOPEX/Poseidon, mission operators carefully control the charging and temperature of the three batteries. Under this TLC approach, the TOPEX/Poseidon batteries have thus far performed exceptionally well. 
    Some of the other components which operators are paying special attention to are the high-gain antenna gimbals, the tape recorders, and the ESAs. Since these components are mechanical and are constantly in use, they are managed such that they are used as efficiently as possible. 
    To date, performance analysis suggests that the first mission-limiting degradation will be from the solar panels, whose output should drop to minimum levels around the year 2000.
